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Stable isotopes of water as a tracer for revealing spatial and temporal characteristics of groundwater recharge surrounding Qinghai Lake,China

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Journal of Mountain Science 2022年第9期19卷 2611-2621页

作者： LI Dong-sheng CUI Bu-li ZHAO yun-duo zuo Feng-lin State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China School of Ocean and Earth Science Tongji UniversityShanghai 200092China School of Resources and Environmental Engineering Ludong UniversityYantai 264025China School of Natural Resources Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Advanced Interdisciplinary Institute of Environment and Ecology Beijing Normal UniversityZhuhai 519087China

Studying spatial and temporal characteristics of regional groundwater recharge will guide the scientific management and sustainable development of regional water *** study investigated stable isotopes(δ^(18)O and δ^(2) H)of precipitation,groundwater,river water and lake water during 2019-2020 in Qinghai Lake Basin to reveal the spatial and temporal characteristics of groundwater *** local meteoric water line was simulated using ordinary least squares regression(δ^(2) H=7.80δ^(18)O+10.60).The local evaporation lines of the river water,lake water and groundwater were simulated asδ^(2) H=6.21δ^(18)O-0.72,δ^(2) H=5.73δ0-3.60 and δ^(2) H=6.59δ0+1.76,*** δ^(2) H and δ^(18)O of river water and groundwater were in more depleted values due to the recharge by precipitation at high altitudes or precipitation effects,and theδ^(2) H andδ^(18)O of the lake water were in more enriched values because of *** relationship between the δ^(2) H and δ^(18)O of groundwater and river water was not significantly different,indicating a strong hydrological connection between the groundwater and river water surrounding Qinghai ***,the maximum values of δ^(18)O and the minimum values of lc-excess of groundwater in most regions were both in August,and the minimum values of δ^(18)O and the maximum values of lc-excess of groundwater in most regions were both in ***,the groundwater was recharged by soil water with strong evaporation in August and recharged by precipitation at high altitudes in *** recharge rate of groundwater was relatively fast in areas with large slopes and large hydraulic gradients(e.g.,south of Qinghai Lake),and in areas with strong hydrological connections between the groundwater and river water(e.g.,the Buha River Valley).Those results can provide data support for protection and utilization of water resources in Qinghai Lake Basin,and provide reference for groundwater research in closed lake basi

关键词： Recharge of groundwater Hydrogen and oxygen stable isotopes Line-conditioned excess Surface water and groundwater Qinghai Lake Basin

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Wave propagation of laminated composite plates via GPU-based wavelet finite element method

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Science China(Technological Sciences) 2017年第6期60卷 832-843页

作者： zuo Hao YANG ZhiBo SUN yu XU CaiBin CHEN XueFeng School of Mechanical Engineering Xi 'an Jiaotong University Xi 'an 710049 China State Key Laboratory for Manufacturing Systems Engineering Xi 'an 710049 China

This paper presents a novel parallel implementation technology for wave-based structural health monitoring (SHM) in laminated composite plates. The wavelet-based B-spline wavelet on he interval (BSWI) element is constructed according to Hamilton’s principle, and the element by element algorithm is parallelly executed on graphics processing unit (GPU) using compute unified device architecture (CUDA) to get the responses in full wave field accurately. By means of the Fourier spectral analysis method,the Mindlin plate theory is selected for wave modeling of laminated composite plates while the Kirchhoff plate theory predicts unreasonably phase and group velocities. Numerical examples involving wave propagation in laminated composite plates without and with crack are performed and discussed in detail. The parallel implementation on GPU is accelerated 146 times comparing with the same wave motion problem executed on central processing unit (CPU). The validity and accuracy of the proposed parallel implementation are also demonstrated by comparing with conventional finite element method (FEM) and the computation time has been reduced from hours to minutes. The damage size and location have been successfully determined according to wave propagation results based on delay-and-sum (DAS). The results show that the proposed parallel implementation of wavelet finite element method (WFEM) is very appropriate and efficient for wave-based SHM in laminated composite plates.

关键词： wave propagation laminated composite plates wavelet finite element method parallel implementation structural health monitoring

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An Adaptive Task Creation Pruning Strategy for Optimizing Irregular Applications

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Chinese Journal of Electronics 2015年第3期24卷 535-541页

作者： CAO Qian LI Huiyong zuo Min DENG yun yu yuan School of Computer and Information Engineering Beijing Technology and Business University School of Electronics Engineering and Computer Science Peking University College of Information Science and Engineering Guilin University of Technology

The Open MP task directive makes it possible to efficiently parallelize irregular applications, with task granularity as one of the most critical issues. To implement Open MP specification on multi-core architecture,a model is presented specializing in the execution of irregular applications. The model captures computation and communication within a node with host cores and accelerator cores. Based on this model, we propose an adaptive task creation pruning strategy including two stages to adjust dynamically task granularity. The first stage is task creation in breadth-first manner until getting to a threshold, which utilizes potential parallelism of multi-core processor. The second stage is starvation-triggered task regeneration once some worker thread becomes starved, which ensures work-stealing and thus achieves load balance. The evaluation is conducted with a series of typical irregular benchmarks, and the results indicate that our approach offers more effective performance in parallel execution of irregular benchmarks.

关键词： Task granularity Adaptive Irregular applications Multi-core

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The Composition of Colonic Commensal Bacteria According to Anatomical Localization in Colorectal Cancer

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Engineering 2017年第1期3卷 90-97页

作者： Liuyang Zhao Xiang Zhang Tao zuo Jun yu Institute of Digestive Disease Department of Medicine and Therapeutics State Key Laboratory of Digestive Disease Li Ka Shing Institute of Health Sciences The Chinese University of Hong Kong Hong Kong China Shenzhen Research Institute. The Chinese University of Hong Kong Shenzhen S18057 China

Colorectal cancer （CRC） is a multistage disease resulting from complex factors, including genetic mutations, epigenetic changes, chronic inflammation, diet, and lifestyle. Recent accumulating evidence suggests that the gut microbiota is a new and important player in the development of CRC. Imbalance of the gut microbiota, especially dysregulated gut bacteria, contributes to colon cancer through mechanisms of inflammation, host defense modulations, oxidative stress, and alterations in bacterial-derived metabolism. Gut commensal bacteria are anatomically defined as four populations： luminal commensal bacteria, mucus-resident bacteria, epithelium-resident bacteria, and lymphoid tissue-resident commensal bacteria. The bacterial flora that are harbored in the gastrointestinal （GI） tract vary both longitudinally and cross-sectionally by different anatomical localization. It is notable that the translocation of colonic commensal bacteria is closely related to CRC progression. CRC-associated bacteria can serve as a noninvasive and accurate biomarker for CRC diagnosis. In this review, we summarize recent findings on the oncogenic roles of gut bacteria with different anatomical localization in CRC progression.

关键词： Microbiota Colorectal cancer Luminal commensal bacteria Translocation Biomarker

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Effect of activators on the properties of nickel coated diamond composite powders

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Journal of Materials Science & Technology 2017年第11期33卷 1409-1415页

作者： Zongshi zuo Bonian Hu Hong Chen Qizhi Dong Gang yu State Key Laboratory of Chemo/Biosensing and Chemometrics College of Chemistry and Chemical Engineering Hunan University Department of Materials and Chemical Engineering Hunan Institute of Technology School of Materials Science and Energy Engineering Foshan University

Nickel coated diamond composite powders were fabricated via a newly developed direct electrodeposition technique. The effects of activators on the coating of diamond were firstly investigated and diamond grinding wheels were then prepared from Ni-coated diamond composite powders with different activators. The microstructural characterizations of this composite powders were finally conducted by scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction, and the mechanical and tribological properties of as-prepared diamond grinding wheels were also measured. There are changes in microstructures and properties of the composite powders with activators. The activator concentration also has an influence on the morphologies and phase structures of the Ni coating on diamond *** composite powders with more compact coating of nickel can be prepared by adding 1 g dm^（-3） or more AgNO_3 as an activator to electrodeposit nickel on diamond. The mechanical and tribological properties of diamond grinding wheels were significantly improved when the coating phase structure of Ni crystal grew with（111） plane orientation on the surface of diamond particles. The wheels made from nickel coated diamond composite powders possessed the advantages of easy preparation and outstanding tribological properties. Therefore, Ni coated diamond composite powders exhibit a great potential to be extensively applied in diamond cutting and grinding tools.

关键词： Composite powders Nickel coated diamond Activator Direct electrodeposition Phase structure Tribological property

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Microstructure and Oxidation Behaviors of Nano-particles Strengthened NiCoCrAlY Cladded Coatings on Superalloys

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Chinese Journal of Mechanical Engineering 2010年第3期23卷 297-304页

作者： WANG Hongyu zuo Dunwen CHEN Xinfeng yu Shouxin GU yuanzhi Jiangsu Provincial Key Laboratory of Precision and Micro-manufacturing Technology Nanjing University of Aeronautics and Astronautics Nanjing 210016 China School of Mechanical Engineering Jiangsu University Zhenjiang 212013 China

Nano-particles which can largely improve the microstructure and oxidation resistance of materials are often used as a strengthening component in metal matrix composites. However, few studies were reported on its application in the bond coat of duplex structure thermal barrier coating（TBC）. Three kinds of NiCoCrAlY coatings strengthened by different nano-particles with the same addition （1%, mass fraction） were prepared by the laser cladding technique on Ni-based superalloy substrates, aiming to study the effects of the nano-particles on microstructure and oxidation resistance of NiCoCrAlY coatings （the bond coat of the duplex structure thermal barrier coatings）. Scanning electron microscope （SEM）, X-ray diffractometer（XRD） and thermogravimetry were employed to investigate their morphologies, phases and cyclic oxidation behaviors in atmosphere at 1 050℃, compared with the coating without nano-particles. With the addition of nano-particles, the growth pattern of the grains at the interface changed from epitaxial growth to non-epitaxial growth or part-epitaxial growth; slender dendrites were broken and cellularized; cracks and pores were restrained; and the oxidation weight-gain and the stripping resistance of the oxide scale were improved as well. Among the three kinds of nano-particles, the SiC nano-particles showed the most improvement on microstructure, while the CeO2 nano-particles were insufficient, but its effects on the oxidation resistance are the same as those of the SiC nano-particles. Based on the discussions of the influence mechanism, it is believed that CeO2 nano-particles would show better improvement than SiC nano-particles if the proper amount is added and the proper preparation technique of micro-nanometer composite powders is adopted, with the synergistic action of nanometer effect and reactive element effect.

关键词： high-temperature protective coating nano-particle microstructure cyclic oxidation laser cladding

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Impact wear properties of dissimilar joints between bainitic frogs and pearlite rails

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Journal of Iron and Steel Research International 2024年第1期31卷 275-287页

作者： Pin-yong Zeng Chun-guang zuo Xiao-yu Zhang Wei Li Tribology Research Institute Southwest Jiaotong UniversityChengdu610031SichuanChina

The impact wear behavior and damage mechanism of dissimilar welded joints between U26Mn frog and U75 V rail before and after normalizing treatment were studied by cyclic impact *** experiment indicated that the impact wear volume of the joints increased with the increasing number of impact *** main wear mechanisms include pitting wear,mild fatigue wear,delamination wear,and fatigue wear,and plastic deformation was the primary impact wear *** them,fatigue wear had the greatest influence on wear volume,while other wear mechanisms had limited *** impact wear resistance of the base material was better than that of the heat-affected *** treatment was beneficial to improving the impact wear resistance of welded joints owing to its effect to promote pearlite recovery,grain refinement,and uniform distribution of *** martensite generated in the rail welded joints aggravated the impact wear damage to the materials,which should be avoided.

关键词： Dissimilar welded joint Impact wear Bainitic steel Damage mechanism Wear rate

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Heavy metals in surface sediments from Minjiang Estuary-Mazu and Xiamen-Jinmen sea areas

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Journal of Environmental Sciences 2003年第1期15卷 116-122页

作者： HONGLi－yu HONGHua－sheng 等 KeyLaboratoryforMarineEnvironmentalScienceofMinistryofEducation／EnviromentalScienceReserachCenter XiamenUiversityiXiamen361005China KeyLaboratoryforMarineEnvironmentalScienceofMinistryofEducation／En

The concentrations of Cu, Pb, Zn and Cd in surface sediments from Minjiang Estuary\|Mazu and Xiamen\|Jinmen sea areas of China were investigated during 1995—1996. The concentration ranges of Cu, Pb, Zn and Cd in the Minjiang Estuary\|Mazu sea area were 16.4\_ 37.2, 33.4\_69.6, 92.1\_128, 0.087\_0.336 mg/kg(dry wt.), respectively; those for Xiamen\|Jinmen sea area were 11.0\_24.5, 36.0\_80.3, 77.5\_161, 0.135\_0.285 mg/kg(dry wt.), respectively. The concentrations and distributions of Cu, Pb, Zn and Cd in surface sediments of Minjiang Estuary\|Mazu and Xiamen\|Jinmen sea areas were analyzed and evaluated. The results showed that the values of Zn and Pb exceeded those of sediment quality criteria. The average concentration of Cu in Minjiang Estuary\|Mazu sea area was higher than that in Xiamen\|Jinmen sea area. The obviously higher concentrations of Cu, Pb, Zn and Cd were found at outlets of Minjiang and Jiulong River. From the estuaries to open sea, the concentrations of Cu, Pb, Zn and Cd had a decreasing trend, and then elevated in the sea areas near Mazu and Jinmen, suggesting that Cu, Pb, Zn and Cd in Minjiang Estuary\|Mazu and Xiamen\|Jinmen sea areas may come from both the mainland and Taiwan of China.

关键词： heavy metal sediment concentration distribution Minjiang Estuary\|Mazu and Xiamen\|Jinmen sea areas

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Some Minimax Problems in Lexicographic Order

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Acta Mathematicae Applicatae Sinica 2017年第1期33卷 193-200页

作者： yu ZHANG sheng-jie LI College of Statistics and Mathematics Yunnan University of Finance and Economics College of Mathematics and Statistics Chongqing University

In this paper, minimax theorems and saddle points for a class of vector-valued mappings f（x, y） = u（x）＋ β（x）v（y） are first investigated in the sense of lexicographic order, where u, v are two general vector-valued mappings and β is a non-negative real-valued function. Then, by applying the existence theorem of lexicographic saddle point, we investigate a lexicographic equilibrium problem and establish an equivalent relationship between the lexicographic saddle point theorem and existence theorem of a lexicographic equilibrium problem for vector-valued mappings.

关键词： vector Optimization Minimax theorem Lexicographic saddle point lexicographic equilibriumproblem

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Mathematical model of burden distribution in bell-less top blast furnace

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Journal of Iron and Steel Research International 2023年第2期30卷 216-226页

作者： Jian-sheng Chen Hai-bin zuo Jing-xiu Wang Qing-guo Xue Jing-song Wang State Key Laboratory of Advanced Metallurgy University of Science and Technology BeijingBeijing100083China

The burden distribution in the shaft of blast furnace is known to affect the gas distribution,heat transfer,and chemical reactions inside the ***,the internal layer structure of burden in the shaft cannot be directly ***,a mathematical model for evaluating burden profile and layer structure was established.A sensitivity analysis based on the model was implemented to elucidate the effect of some factors on the burden distribution,including the stockline height and the mass of central *** results show that the width of funnel zone widens with the increase in stockline height,and the mass percentage of ore to coke in this zone slightly ***,the mass of central coke shows a significant influence on the width of coke channel,and 2%of batch mass of coke is recommended to implement central coke charging *** model has been indirectly verified by the gas temperature in operating blast furnace and successfully applied to online evaluate burden distribution.

关键词： Blast furnace Burden distribution Mathematical model Stockline height Central coke

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